BELGRADE, Yugoslavia -- The wounds of war and world condemnation are causing a historic split between Serbs in the Yugoslav heartland and fellow Serbs in Bosnia that is shifting the ground beneath the war effort, interviews with politicians, voters and diplomats revealed.

Across a spectrum of economic and intellectual classes, Serbs in the republic of Serbia -- the central republic of old Yugoslavia -- are angered that they are labeled the aggressor state for acts of war carried out by ethnic Serbs native to neighboring Bosnia.

While most Serbs here remain intensely loyal to the Serbian cause, they are calling for a negotiated settlement, and some are demanding the resignation of Serbian President Slobodan Milosevic.

There is no denying that Mr. Milosevic whipped up nationalist emotions as he led the campaign to salvage communist Yugoslavia as a Greater Serbia stretching from Romania to the Adriatic.

It also was at his command that the old Yugoslav federal army, in its death throes, armed Serbian irregulars living in Bosnia to carry out that plan, and in fact have even joined the irregulars.

But Serbs in the home republic, while correctly arguing that atrocities were carried out by Croatians and Muslims as well, are beginning to lift the veil off state-controlled media. With that comes an awareness of evidence that Serb irregulars in Bosnia run prisoner camps and wage "ethnic cleansing" on a scale greater than their foes.

Members of the opposition who hope to oust Mr. Milosevic now make the excesses of Bosnian Serbs a central plank of their platform, even as they try to reassure themselves that the average Serb in Serbia was, at worst, guilty only of passively allowing atrocities to occur.

"The mistake of not keeping the situation under control was made at the very beginning," said Dragoljub Micunovic, president of the opposition Serbian Democratic Party.

A Western diplomatic observer declined to rule out that conflicts within the family of Southern Slavs could be "a dress rehearsal for a Serbian civil war."

The diplomat said Western embassies in Belgrade were receiving reports that official Serbian police and militia units in Bosnia and in Montenegro are battling local Serbian warlords suspected of war crimes, as well as gangs who want to lengthen the conflict to plunder the countryside.

In interviews with factory workers, homemakers, college professors -- and even fighters just back from the front -- an outline of a new "reasonable center" in Serbian politics may be seen to emerge, one committed to ending the war.

These people rankle at any discussion of dismembering Serbia from such adjacent regions as Kosovo or Vojvodina. But they are tired of war and would be willing to vote for a change in leadership in November's election if that would speed a negotiated settlement.

Their lives have been made difficult by half-mile-long lines for gasoline. And prices for medicine and food are soaring out of reach for those whose salaries have been halved by production slowdowns in every factory because of dwindling supplies of raw materials.

But just as emotions are swinging toward ending the war, it is clear that any outside military intervention regarded as specifically anti-Serbian would re-cement ties among branches of the Serbian family and send the population again rallying around Mr. Milosevic.

"Everybody I know wants an end to the war, and if that means Milosevic has to go, well then so be it," said Zoran Kocic, who recently lost his job at a furniture factory that was shuttered when fuel ran low.

"But you in the West have to remember one of the most important aspects of Serbian character," he said. "And it is called inat."

He said inat can best be translated as spite, but a spitefulness born of wanting to prove one's critics wrong. "You should not send in bombers but let us solve it," Mr. Kocic added.

Members of the political opposition believe that Mr. Milosevic senses this changing tide of public opinion and that this explains why he opened roundtable talks last week with opposition leaders amid hints that he may not seek re-election in November.